A U.S. Navy EA-18G Growler recently made it back to base after suffering a terrifying mid-air mishap, which left its two-person crew flying blind and frostbitten after the aircraft’s environment control system failed in part thanks to a pair of high-tech wrist watches. The incident occurred just over a year after the canopy on another one of the electronic warfare planes exploded in a bizarre over-pressurization incident and as the service continues to struggle to find exactly what’s causing persistent reports of “hypoxia-like” symptoms across the F/A-18 Hornet, F/A-18E/F Super Hornet, and Growler fleets.

Defense News was first to report this new incident, which occurred approximately 60 miles south of Seattle, Washington. The EA-18G, assigned to Air Test and Evaluation Squadron Nine (VX-9), was flying at approximately 25,000 feet on a mission from Naval Air Station Whidbey Island, between Seattle and Vancouver BC, when the cockpit temperature plummeted to -30 degrees Fahrenheit.

The broken environmental control system (ECS) also let in a fine mist of liquid, which then froze, coating the inside of the canopy and vital flight instruments in an opaque sheen of ice. The ECS consists of a number of sub-components that are supposed to work together to manage oxygen flow to the crew, as well as cockpit pressure and temperature. An US Navy EA-18G Growler. A Navy deck crewman wipes down an EA-18G. A test fixture the Naval Air Warfare Center Aircraft Division Altitude Lab uses to test breathing apparatuses and OBOGS systems. A US Navy T-45A Goshawk trainer, another type of aircraft that has suffered serious problems with its OBOGS.